How can I set the camera parameters for 3d motion tracking footage?
There is no need to un-squeeze the anamorphic pixels as an extra step (specially if you have already de-interlaced it, so you are dealing with a degraded original to begin with), just enter the aspect ratio in the Track &gt; Camera &gt; Pixel Aspect section.

For the sensor width enter the value you know and set the lens to 5.4mm
You can try to find the radial distortion coefficients (k1, k2) using the annotation tool. The procedure is outlined in this post:
How to determine lens undistortion values for motion tracking?
But Blender will optimize those settings in the solve if you set the refine settings to Focal Length, Optical Center, K1, K2.

At the time of solving and refining blender usually gets those parameters quite accurately.

You should aim for an error average of less than 1/3 of a pixel (0.3)
For accurate tracking and solving, please read the very detailed post on motion tracking:
How can I get better results when doing camera motion tracking?